Check whether n is prime

Python program to check whether a number is Prime or not - GeeksforGeeks

code is from above.

The first code has a bug (when n is 4 will give the wrong answer) and I fixed it. The fixed one is below:

def is_prime(num):
            if num > 1: 
                for i in range(2, num//2+1):
                    if num%i==0:return False
                return True
            else:
                return False
def is_prime(n) : 
  
            # Corner cases 
            if (n <= 1) : 
                return False
            if (n <= 3) : 
                return True
  
            # This is checked so that we can skip  
            # middle five numbers in below loop 
            if (n % 2 == 0 or n % 3 == 0) : 
                return False
  
            i = 5
            while(i * i <= n) : 
                if (n % i == 0 or n % (i + 2) == 0) : 
                    return False
                i = i + 6
  
            return True

Or we can write the second one in a more concise way

def is_prime(n):
            if n<=1:return False
            if n==2 or n==3:return True
            if n%2==0 or n%3==0:return False
            for i in range(5, int(n**0.5)+1, 6):
                if n%i==0 or n%(i+2)==0:return False
            return True

866. Prime Palindrome

This problem is using this function to check whether a num is prime or not.